Colloid Facilitated Transport of Radioactive Cesium in a Fukushima Soil.

Cesium is a large atom which does not likely to hydrate. Similar to potassium and ammonium it prefers to site at siloxane ditrigonal cavity of silica sheet of phyllosilicates. Cesium is strongly, almost irreversibly, captured at frayed edge site. These facts may make partition coefficient of cesium to be very large. The large partition coefficient may produce larger retardation of cesium transport. However, early observation after the accident of Fukushima nuclear power plant suggested quick transport of cesium occurred soon after the accident. This quick transport of cesium could be due to colloid-facilitated transport. Column experiment with organic colloids extracted from litter of Iitate village, Fukushima by pure water suggested under a limited condition organic colloids are promoter of cesium transport in Fukushima soils.